Kicker power supply for J-PARC 3-GeV RCS with SiC-MOSFET

Takayanagi, Tomohiro; Ono, Ayato; Ueno, Tomoaki*; Horino, Koki*; Togashi, Tomohito; Yamamoto, Kazami; Kinsho, Michikazu; Koizumi, Isao*; Kawamata, Shunsuke*

JPS Conference Proceedings (Internet), 33, p.011020_1 - 011020_6, 2021/03

https://doi.org/10.7566/JPSCP.33.011020

We are developing a new kicker power supply for J-PARC 3-GeV RCS (Rapid-Cycling Synchrotron) using the next generation power semiconductor SiC-MOSFET with high withstand voltage, low loss, and superior high frequency characteristics. The three major circuits adopted for the RCS kicker power supply, the thyratron switch, the PFN circuit of coaxial cable type, and the end clipper for reflection wave absorption, has been realized with a single modular circuit board based on the LTD circuit. The new kicker power supply realizes stable operation, miniaturization and energy saving by using power semiconductors. The required high voltage can be output by stacking the 800V/2kA modular circuit board in series. The details of circuit design and the results of achieving an output of half 20kV/2kA against the target specification of 40kV/2kA are presented here.

Progress of divertor simulation research toward the realization of detached plasma using a large tandem mirror device

Nakashima, Yosuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Oki, Kensuke*; Sakamoto, Mizuki*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; Imai, Tsuyoshi*; et al.

Journal of Nuclear Materials, 463, p.537 - 540, 2015/08

https://doi.org/10.1016/j.jnucmat.2014.12.063

Development of divertor simulation research in the GAMMA 10/PDX tandem mirror

Nakashima, Yosuke*; Sakamoto, Mizuki*; Yoshikawa, Masayuki*; Oki, Kensuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; et al.

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10

Decommissioning program and future plan for Research Hot Laboratory, 2

Koya, Toshio; Nozawa, Yukio; Hanada, Yasushi; Ono, Katsuto; Kanazawa, Hiroyuki; Nihei, Yasuo; Owada, Isao

Dekomisshoningu Giho, (42), p.41 - 48, 2010/09

http://www.randec.or.jp/publish/documents/gihou/Decommissioning%20gihou_42.pdf

The Research Hot Laboratory (RHL) in Japan Atomic Energy Agency (JAEA) had been contributed to R&D program for fuels and nuclear materials in or out of JAEA. However, the decommissioning work of RHL has been started on April 2003 as the rationalization program for decrepit facilities in former Tokai institute. This work will be progressing, dismantling the lead cells and decontamination of concrete caves then release in the regulation of controlled area. The partial area of RHL will be used for the central storage of un- irradiated fuel and for temporary storage of radioactive device generated by J-PARC. The 18 lead cells had been dismantled and the preparing work for remained 20 lead cells has been finished including the removal of the applause from the cells, survey of the contamination revel in the lead cells and prediction of radio active waste. The future plan of decommissioning work has been prepared to incarnate the basic vision and dismantling procedure.

Performance-based improvement of the leakage rate test program for the reactor containment of HTTR; Adoption of revised test program containing "Type A, Type B and Type C tests"

Kondo, Masaaki; Kimishima, Satoru*; Emori, Koichi; Sekita, Kenji; Furusawa, Takayuki; Hayakawa, Masato; Kozawa, Takayuki; Aono, Tetsuya; Kuroha, Misao; Ouchi, Hiroshi

JAEA-Technology 2008-062, 46 Pages, 2008/10

JAEA-Technology-2008-062.pdf:11.62MB

The reactor containment of HTTR is tested to confirm leak-tight integrity of itself. "Type A test" has been conducted in accordance with the standard testing method in JEAC4203 since the preoperational verification of the containment was made. Type A tests are identified as basic one for measuring containment leakage rate, it costs much, however. Therefore, the test program for HTTR was revised to adopt an efficient and economical alternatives including "Type B and Type C tests". In JEAC4203-2004, following requirements are specified for adopting alternatives: upward trend of leakage rate by Type A test due to aging should not be recognized; criterion of combined leakage rate with Type B and Type C tests should be established; the criteria for Type A test and combined leakage rate test should be satisfied; correlation between the leakage rates by Type A test and combined leakage rate test should be recognized. Considering the performances of the tests, the policies of corresponding to the requirements were developed, which were accepted by the regulatory agency. This report presents an outline of the tests, identifies issues on the conventional test and summarizes the policies of corresponding to the requirements and of implementing the tests based on the revised program.

Confirmation tests for fabrication of low density MOX pellet for FBR

Murakami, Tatsutoshi; Suzuki, Kiichi; Hatanaka, Nobuhiro; Hanawa, Yukio; Shinozaki, Masaru; Murakami, Shinichi; Tobita, Yoshimasa; Kawasaki, Takeshi; Kobayashi, Yoshihito; Iimura, Naoto; et al.

JAEA-Technology 2008-017, 97 Pages, 2008/03

JAEA-Technology-2008-017.pdf:2.76MB

Low density MOX pellets for FBR "MONJU" have not been fabricated in Plutonium Fuel Fabricating Facility (PFPF) for these 9 years since completion of the first reload fuel for "MONJU" in 1995. In this period, about 60 % of machines in the pellet fabrication process of PFPF have been replaced with new ones, and fabrication of MOX pellets for "JOYO" has been continued using these machines. Concerning the feed MOX powders for "MONJU", the amount of decay heat has been increased with increase of accumulated Am-241 in this period. In addition, powder characteristic of recycled MOX powder which is one of feed powders, MH-MOX powder, UO powder and recycled MOX powder, was significantly changed by replacing former processing machine used for scrap recycling with improved one. Using MOX powder with increased decay heat and recycled MOX powder processed by new machine, a series of low density MOX pellet fabrication tests were conducted to confirm pellet fabrication conditions for current pellet fabrication machines from October in 2004 to August in 2006. As a conclusion, it was confirmed that low density MOX pellets could be fabricated using these feed powders and replaced machines by adjusting pellet fabrication conditions adequately. This report summarizes the results of a series of low density MOX pellet fabrication tests.

Single crystalline -FeSi grown using high-purity FeSi source

Goto, Kohei*; Suzuki, Hirokazu*; Udono, Haruhiko*; Kikuma, Isao*; Esaka, Fumitaka; Uchikoshi, Masahito*; Isshiki, Minoru*

Thin Solid Films, 515(22), p.8263 - 8267, 2007/08

https://doi.org/10.1016/j.tsf.2007.02.066

We have investigated the effect of FeSi source purity on the electrical property of -FeSi grown from solution. A high purity FeSi source avoided a contamination of Cu and W metals was synthesized by melting a high purity Fe (5N) and Si (5N-up) in a quartz ampoule. The -FeSi crystals grown using the high purity FeSi and Zn solvent showed n-type conduction, whereas those grown using the arc-melted FeSi showed p-type. From the SIMS analysis of the grown crystals, we found that dominant impurity concentrations in the p-type crystals were higher than those in the n-type ones.

Leakage rate test for reactor containment vessel of HTTR

Kondo, Masaaki; Sekita, Kenji; Emori, Koichi; Sakaba, Nariaki; Kimishima, Satoru; Kuroha, Misao; Noji, Kiyoshi; Aono, Tetsuya; Hayakawa, Masato

JAEA-Testing 2006-002, 55 Pages, 2006/07

JAEA-Testing-2006-002.pdf:6.36MB

The leakage rate test for the reactor containment vessel of HTTR is conducted in accordance with the absolute pressure method provided in Japan Electric Association Code(JEAC4203). Although leakage test of a reactor containment vessel is, in general, performed in condition of reactor coolant pressure boundary to be opened in order to simulate an accident, the peculiar test method to HTTR which use the helium gas as reactor coolant has been established, in which the pressure boundary is closed to avoid the release of fission products into the environment of the reactor containment vessel. The system for measuring and calculating the data for evaluating the leakage rate for containment vessel of HTTR was developed followed by any modifications. Recently, the system has been improved for more accurate and reliable one with any useful functions including real time monitoring any conditions related to the test. In addition, the configuration of containment vessel boundary for the test and the calibration method for the detectors for measuring temperature in containment vessel have been modified by reflecting the revision of the Code mentioned above. This report describes the method, system configuration, and procedures for the leakage rate test for reactor containment vessel of HTTR.

Isolated hydrogen center in wide gap semiconductors studied by SR

Shimomura, Koichiro*; Kadono, Ryosuke*; Nishiyama, Kusuo*; Watanabe, Isao*; Suzuki, Takao*; Pratt, F.*; Oishi, Kazuki; Mizuta, Masashi*; Saito, Mineo*; Chow, K. H.*; et al.

Physica B; Condensed Matter, 376-377, p.444 - 446, 2006/04

https://doi.org/10.1016/j.physb.2005.12.114

Status of J-PARC muon science facility at the year of 2005

Miyake, Yasuhiro*; Nishiyama, Kusuo*; Kawamura, Naritoshi*; Makimura, Shunsuke*; Strasser, P.*; Shimomura, Koichiro*; Beveridge, J. L.*; Kadono, Ryosuke*; Fukuchi, Koichi*; Sato, Nobuhiko*; et al.

Physica B; Condensed Matter, 374-375, p.484 - 487, 2006/03

https://doi.org/10.1016/j.physb.2005.11.136

The construction of the Materials and Life Science building was started in the beginning of the fiscal year of 2004. After commissioning of the accelerator and beam transport sections in 2008, muon beams will be available for users in 2009. In this letter, the latest construction status of the J-PARC Muon Science Facility is reported.